(P) Nucleic Acids and Code of Life (ppt-based)

Question 1

Who postulated the central dogma of molecular biology?

Answer 1

Francis Crick

Question 2

How will RNA form appropriate proteins?

Answer 2

Translation

Question 3

process that produces new
DNA molecules

Answer 3

replication

Question 4

Refers to the 2 strands of the DNA being separated & each single single strand resulting in the formation of 2 daughter strand each of which is an exact copy of the original molecule.

Answer 4

semiconservative

Question 5

What phase does DNA replication occur?

Answer 5

S Phase

Question 6

T or F. DNA replication is BIDIRECTIONAL.

Answer 6

T

Question 7

points at which new polynucleotide chains are formed

Answer 7

replication forks

Question 8

How many replication forks per origin of replication?

Answer 8

2

Question 9

separates the DNA strands; breaks the H-bonds between the base pairs

Answer 9

Helicase

Question 10

prevents the separated template stands from reforming double helix; prevent degradation of ssDNA

Answer 10

SSB proteins

Question 11

how does SSB proteins prevent degradation?

Answer 11

by exonucleases

Question 12

This reaction catalyzes the copying of a short stretch of the DNA template strand to produce RNA primer sequence

Answer 12

Primase reaction

Question 13

Major enzyme; starter of the DNA replication

Answer 13

primase

Question 14

A DNA polymerase requires a____ to start DNA synthesis

Answer 14

primer

Question 15

provides the OH grp where the new nucleotide is added

Answer 15

RNA primer

Question 16

It begins synthesizing DNA in the 5’->3’ direction, begining at 3’ end of RNA fragment

Answer 16

DNA polymerase III

Question 17

an enzyme responsible for joining the nucleotide triphosphate fragments to produce daughter strands of DNA.

Answer 17

DNA polymerase

Question 18

How is the leading strand synthesized?

Answer 18

CONTINUOUSLY in the 5’-> 3’ direction toward the replication fork

Question 19

How is the lagging strand synthesized?

Answer 19

semidiscontinuously in 5’->3’ direction away from the replication fork

Question 19

requirement of DNA polymerase

Answer 19

all four deoxyribonucleoside triphosphates (dNTPs): dTTP , dATP, dGTP, and dCTP, Mg2+, and an RNA primer

Question 20

synthesis, proofreading, and repair
of lagging strand

Answer 20

DNA Pol 1

Question 21

replaces the RNA primers with DNA nucleotides in lagging strand.

Answer 21

DNA Pol 1

Question 22

proofreading &repair enzymes

Answer 22

DNA Pol II, IV, and V

Question 23

the main enzyme of DNA synthesis

Answer 23

DNA Pol III

Question 24

this enzyme simultaneously produce DNA on both leading strand and lagging strand

Answer 24

DNA Pol III

Question 25

In removing RNA primers, what enzyme is used in eukaryotes?

Answer 25

RNAase H

Question 26

What happens after the removal of RNA primers in eukaryotes?

Answer 26

the DNA pol. fills the gap with DNA

Question 27

In removing RNA primers, what enzyme is used in prokaryotes?

Answer 27

DNA pol I: removes the primer (5'-3' exonuclease activity)

Question 28

What happens after the removal of RNA primers in prokaryotes?

Answer 28

synthesis of new DNA

Question 29

refers to removal of incorrect nucleotides immediately after they are added to the growing DNA during the replication process.

Answer 29

Proof reading

Question 30

What is the proof reading activity?

Answer 30

DNA Pol 1; 3' exonuclease activity - remove the incorrect nucleotide

Question 31

T or F. Replication repeats when the correct nucleotide is added after proofreading.

Answer 31

F (resume lang, 'di n sya uulit beh)

Question 32

Seals the gap between the Okazaki pieces (DNA fragments)

Answer 32

DNA ligase

Question 33

In sealing the nicks using DNA ligase, it forms which kind of bond?

Answer 33

phosphodiester bonds

Question 34

T or F. In eukaryotes, polymerases are also exonucleases.

Answer 34

F (prokaryotes)

Question 35

T or F. Prokaryotes have longer okazaki fragments of 1000 to 2000 residues compares to eukaryotes of 150-200 long

Answer 35

T

Question 36

T or F. Prokaryotes have histones that are normally complexed to DNA.

Answer 36

F (eukaryotes)

Question 37

T or F both eukaryotic and prokaryotic cells have multiple ori (origin of replication) sites per chromosome

Answer 37

F (prokaryotes only have one ori site per chromosome)

Question 38

Unwinds the DNA double helix for both prokaryotic and eukaryotic cells

Answer 38

helicase

Question 39

this enzyme synthesizes RNA primers

Answer 39

primase

Question 40

T or F Double-stranded-DNA binding proteins (DSB) stabilizes unwound template strands

Answer 40

F Single stranded dna binding proteins (ssb)

Question 41

this enzyme synthesizes the lagging and leading strand in prokaryotic cells

Answer 41

DNA polymerase III

Question 42

Synthesizes the leading and lagging strand in eukaryotic cells

Answer 42

DNA polymerases alpha and delta

Question 43

Removes RNA primers for prokaryotes

Answer 43

DNA polumerase I

Question 44

Removes RNA primers for eukaryotes

Answer 44

RNAase H

Question 45

Joins Okazaki fragments

Answer 45

DNA ligase

Question 46

Removes positive supercoils instead of advancing replication forks

Answer 46

DNA topoisomerase II

Question 47

Main polymerizing enzyme in prokaryotes

Answer 47

polymerase III

Question 48

Main polymerizing enzyme in eukaryotes

Answer 48

polymerase delta

Question 49

T or F Not all polymerases are exonucleases in eukaryotes

Answer 49

T

Question 50

T or F There are no proteins complexed to DNA in prokaryotes

Answer 50

T

Question 51

this are complexed to DNA in eukaryotic cells

Answer 51

Histones

Question 52

T or F in Eukaryotes, Okazaki fragments are 250 - 300 residues long

Answer 52

F (150-200)

Question 53

length of Okazaki fragments in prokaryotes

Answer 53

1000-2000 Residues long